Custom development
When no existing tool does what you need, we build the web application that does, and we price the project before we start.
An application to…
organise and join local activities
Plannrfind an eco-friendly restaurant near a campus
Isep’Eatbring together the members of a music association
ISEP Bandsmeasure the carbon footprint of a site’s pages
Grammage
How we build
We design the screens in Figma with you, and we only start coding once the mock-up is approved.
The technology adapts to each client: we pick modern open source or well-established technologies, built to scale.
The quote details every line before we start. Pages stay light, and we measure their weight with Grammage.
What we have already built
A platform for organising and joining local activities between individuals.
PlannrA map of eco-friendly restaurants around the Isep campuses, with their opening hours, their offers and a waste score.
Isep’EatThe website of a music association, with its bands, its events and a members’ area.
ISEP BandsThe website of a telecom operator for small and mid-sized businesses, with an address eligibility test and its own administration area.
ZEtelecomA satellite internet offer for businesses, which takes over when the main line goes down.
Sat AccessOur eco-design audit tool, which measures the carbon footprint of pages on every release.
Grammage
Taking over an existing application
Your application still does its job, but it has become hard to evolve. We carry over your accounts, your data and everyone’s access rights, then we redesign the screens on a recent technical base.

What an application costs
Two packages to place your project. The quote then lists every screen and every feature, line by line, before we start.
Application
To launch an idea, or to replace spreadsheets and email threads with a real working tool.
From€9,000 excl. VATLive in 2 to 4 months
- User accounts and sign-in
- Roles and permissions for each team
- An admin area for your data
- Figma mock-ups, approved with you
- Launch on our servers in Paris
Custom
For several applications, a mobile app or large volumes.
PriceOn quoteTimeline set in the quote
- A specification written with you
- The project split into stages delivered one by one
- The price of each stage fixed before it starts
Options, to adjust the quote
What can be added to a package, with its price.
Content and languages
Extra language
€400
Setup and translation, then €250 for each further language.
Bookings and statistics
Custom booking
From €800
Time slots, services and a deposit, then priced to your needs.
Visit statistics
€150
Google Analytics 4, with a GDPR-compliant cookie banner.
Admin and software
Admin area
From €1,200
You edit your texts and photos yourself.
Connection to a service
From €300
Your management, invoicing or customer software connected to your website.
Development day
For anything outside this list, such as an application feature, priced in days in the quote.
€420 a day
Frequently asked questions
Another question? Write to us at [email protected].
How much does a custom application cost?
Can you take over an application I already have?
Should my application be rebuilt or repaired?
How do I know whether I need a custom application?
Your application
Tell us what you need and we will reply with a quote for your application.